library/alloc/tests/heap.rs

   1 use std::alloc::{AllocInit, AllocRef, Global, Layout, System};
   2
   3 /// Issue #45955 and #62251.
   4 #[test]
   5 fn alloc_system_overaligned_request() {
   6     check_overalign_requests(System)
   7 }
   8
   9 #[test]
  10 fn std_heap_overaligned_request() {
  11     check_overalign_requests(Global)
  12 }
  13
  14 fn check_overalign_requests<T: AllocRef>(mut allocator: T) {
  15     for &align in &[4, 8, 16, 32] {
  16         // less than and bigger than `MIN_ALIGN`
  17         for &size in &[align / 2, align - 1] {
  18             // size less than alignment
  19             let iterations = 128;
  20             unsafe {
  21                 let pointers: Vec<_> = (0..iterations)
  22                     .map(|_| {
  23                         allocator
  24                             .alloc(
  25                                 Layout::from_size_align(size, align).unwrap(),
  26                                 AllocInit::Uninitialized,
  27                             )
  28                             .unwrap()
  29                             .ptr
  30                     })
  31                     .collect();
  32                 for &ptr in &pointers {
  33                     assert_eq!(
  34                         (ptr.as_ptr() as usize) % align,
  35                         0,
  36                         "Got a pointer less aligned than requested"
  37                     )
  38                 }
  39
  40                 // Clean up
  41                 for &ptr in &pointers {
  42                     allocator.dealloc(ptr, Layout::from_size_align(size, align).unwrap())
  43                 }
  44             }
  45         }
  46     }
  47 }